<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button id="button">button</button>
    <ul id="container"></ul>
    <script>
        document.getElementById('button').addEventListener('click',function() {
            let now = new Date();
            // 插入一万条
            const total = 10000;
            let ul = document.getElementById('container');
            const oFragment = document.createDocumentFragment()
            for(let i = 0; i<total; i++) {
                let li = document.createElement('li');
                li.innerText = Math.ceil(Math.random()*total);
                // ul.appendChild(li)
                oFragment.appendChild(li)
            }
            ul.appendChild(oFragment)
            console.log('js 运行时间:',Data.now() - now)
            setTimeout(() => {
                console.log('js 运行时间:',Data.now() - now)
            }, 0);
        })
    </script>
</body>
</html>